On Tuesday, November 27, 2018 at 6:07:41 PM UTC-6, [email protected] wrote: > > > > On Tuesday, November 27, 2018 at 10:47:08 PM UTC, Philip Thrift wrote: >> >> >> >> On Tuesday, November 27, 2018 at 3:55:16 PM UTC-6, [email protected] >> wrote: >>> >>> >>> >>> On Tuesday, November 27, 2018 at 8:43:55 PM UTC, Philip Thrift wrote: >>>> >>>> >>>> >>>> On Tuesday, November 27, 2018 at 2:05:04 PM UTC-6, [email protected] >>>> wrote: >>>>> >>>>> >>>>> >>>>> On Tuesday, November 27, 2018 at 6:49:51 PM UTC, Philip Thrift wrote: >>>>>> >>>>>> >>>>>> >>>>>> On Tuesday, November 27, 2018 at 12:17:08 PM UTC-6, >>>>>> [email protected] wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Tuesday, November 27, 2018 at 6:00:50 PM UTC, Philip Thrift wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Tuesday, November 27, 2018 at 8:43:35 AM UTC-6, >>>>>>>> [email protected] wrote: >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On Tuesday, November 27, 2018 at 9:27:46 AM UTC, Philip Thrift >>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Monday, November 26, 2018 at 3:43:14 PM UTC-6, >>>>>>>>>> [email protected] wrote: >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> *I checked the postulates in Feynman's Sums Over Histories (in >>>>>>>>>>> link provided by Phil) and I see nothing related to waves, as >>>>>>>>>>> expected, and >>>>>>>>>>> thus nothing about collapse of anything. I would suppose the same >>>>>>>>>>> applies >>>>>>>>>>> to Heisenberg's Matrix Mechanics; no waves, no collapse. I suppose >>>>>>>>>>> you >>>>>>>>>>> could say they just produce correct probabilities, and imply >>>>>>>>>>> nothing about >>>>>>>>>>> relative states other than their probabilities (which wave >>>>>>>>>>> mechanics does), >>>>>>>>>>> but certainly nothing about consciousness. To summarize: you're >>>>>>>>>>> right that >>>>>>>>>>> they are "no collapse" theories, but IMO they say nothing about >>>>>>>>>>> consciousness. AG* >>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> In terms of the path-integral (PI) interpretation [ interesting >>>>>>>>>> lecture: >>>>>>>>>> https://www.perimeterinstitute.ca/videos/path-integral-interpretation-quantum-mechanics >>>>>>>>>> >>>>>>>>>> ], there is in effect no waves or wave function, just paths, or >>>>>>>>>> histories, >>>>>>>>>> in the sum-over-histories (SOH) terminology. >>>>>>>>>> >>>>>>>>>> There is still "decoherence" in the SOH (a single history is >>>>>>>>>> ultimately "realized"), but it could be called "selection": a single >>>>>>>>>> history is selected from the total ensemble of multiple and >>>>>>>>>> interfering >>>>>>>>>> histories. E.g. a single point on a screen is "hit" by a photon in >>>>>>>>>> the >>>>>>>>>> double-slit experiment. >>>>>>>>>> >>>>>>>>> >>>>>>>>> *Does "selection" add any insight to the measurement problem; that >>>>>>>>> is, why do we get what we get? And if not, what is its value? TIA, AG >>>>>>>>> * >>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>> If you look at it as a "selection of the fittest" (one history >>>>>>>> surviving from an ensemble of histories), then it's like a form of >>>>>>>> quantum >>>>>>>> Darwinism. The quantum substrate is a cruel world where all histories >>>>>>>> (but >>>>>>>> one) die. >>>>>>>> >>>>>>> >>>>>>> That's not an explanation; rather, a vacuous statement of the >>>>>>> result. AG >>>>>>> >>>>>>>> >>>>>>>> >>>>>> But that is a criticism of Darwinism (*natural selection*) in >>>>>> general. >>>>>> >>>>> >>>>> *Ridiculous comparison IMO. Darwinism posits a changing environment >>>>> and competition among species for niches. Nothing comparable in Quantum >>>>> Darwinism other than all outcomes fail except for one which succeeds in >>>>> each single trial, which we knew from the get-go. AG* >>>>> >>>>>> >>>>>> *Quantum Darwinism* is a theory claiming to explain the emergence of >>>>>> the classical world >>>>>> <https://en.wikipedia.org/wiki/Classical_physics>from >>>>>> the quantum world <https://en.wikipedia.org/wiki/Quantum_mechanics> as >>>>>> due to *a process of **Darwinian >>>>>> <https://en.wikipedia.org/wiki/Charles_Darwin> natural selection >>>>>> <https://en.wikipedia.org/wiki/Natural_selection>*; where the many >>>>>> possible quantum states >>>>>> <https://en.wikipedia.org/wiki/Quantum_states> are selected against >>>>>> in favor of a stable pointer state >>>>>> <https://en.wikipedia.org/wiki/Pointer_state>. >>>>>> [ https://en.wikipedia.org/wiki/Quantum_Darwinism ] >>>>>> >>>>>> - pt >>>>>> >>>>>> >>>>> >>>> >>>> >>>> As for "competition for niches", the histories are in a sense >>>> competing. Perhaps there is some conservation principle at work, so only >>>> one history can win. >>>> >>>> I don't know. Physicists don't know. We're even. :) >>>> >>> >>> *Darwin had a theory or proposal to explain why some changes occur and >>> persist, but Quantum Darwinism doesn't, as far as I can tell. AG * >>> >>>> >>>> - >>>> >>> >> What was the "why" of Darwin's theory? >> > > *Darwin didn't know about DNA, but he hypothesized that specie could > change in time, and he could explain the persistence of some traits and > non-persistence of others by the process of natural selection. In Quantum > Darwinism, there is no concept AFAICT that explains why all paths but one > cease to exist. There is nothing comparable to Darwin's natural selection. > AG * > >> >> >>
The analogy (mapping) between biological selection and quantum selection isn't perfect. But there is no better idea. - pt -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
